Apparatus for determining the frictional qualities of a liquid



Aug 4, 1931-. J. G. DINTILHAC 1,817,739

APPARATUS FOR DETERMINING THE FRICTIONAL QUALITIES OF A LIQUID Filed July 51; 1928 Ulll lll 'l H'H \"PHIII HIII 1 1 Inc/anion- Jean Gear oafla'wlkao,

Patented Aug. 4, 1931 -UNITED STATES PATENT-OFFICE JEAN GEORGES DINTILHAC, O]? PARIS,

FRANCE, ASSIGNOR TO 'IHE SOCIETY YACCO. S. A. 12.," OF PARIS, FRANCE, A FRENCH SOCIETY APPARATUS FOR DETERMINING THE ERICTIONAL QUALITIES OF A. LIQUID Application filed July 31, 1928, Serial No. 296,592, and in Belgium February 3, 1928.

The present invention relates to methods and apparatus for determining the frictional qualities of a liquid and, more particularly, the internal (intermolecular) friction thereof and the coflicient of friction between the liquid and a solid surface.

One of the object-s of the invention is toprovide a method and apparatus for measuring independently (1) the internal friction of any chosen liquid and (2) .the coefficient of friction between said liquid and a chosen surface, both measurements being made, preferably, at high linear velocities.

Other objects will appear in the course of the detailed description now tobe given with reference to the accompanying drawings, in which- Fig. 1 is a partially sectional elevation of one illustrative embodiment of the invention;

Fig. 2 is a plan of the device represented in Fig. 1;

Fig. 3 is an axial section taken through another form of the invention.

Referring to the Figs. '1 and 2 of the drawings, a is .a solid cylinder rotatably mounted on suitable ball-bearings supported by a vertical shaft d driven by a motor 01' at a predetermined speed; I) is a container having lateral cylindrical walls concentric with cylinder a and supported on ball-bearings mounted on a support al Elements a and b are rovided with corrugations, teeth or blades a and b respectively adapted to take hold of the liquid in container 6. The apparatus is completed bya'liquid siipply conduit cfa thermometer f adapted to measure the temperature of the liquid contained in the latter, and a dynamometer e in the form of a wire e connected to weights 6' or other means 40 adapted to exert a measurable traction.

The device shown in Fig. 3 difi'ers only in the orientation of elements a and b which are here arranged horizontally instead of vertically. Container I) should be of sufii- 5 cient diameter to render the frictional effect between the lateral walls and the liquid negligible.

'The device operates as follows :-oil or a similar liquid is oured into container 6, the temperature ereof being first noted,

the motor (1' coupled to shaft d is then set in motionat a measured speed and drives cylinder 0 through the liquid to be measured; teeth a on cylinder (1 take hold of the liquid and set the latterin motion;--this motion is communicated via the liquid to teeth 6 and sets container 6 in motion. It sufiices then-to apply a measurable frictional force by means of-c, e or any equivalentgdynamometer to bring I) to rest and to thus determine the shearing eflect exerted bythe liquid in contact with a and b on the remaining: liquid lying between these elements. By changing the diameter of either a or b i. e. by varying the thickness of the oil layer being measured, coeflicients of internal friction may be obtained for varying oil thicknesses. Similarly, by varying the temperature or.the nature of the liquid or oil, tables of coeflicients may be established relatively to any given temperature or to any liquid chosen as a standard. It is important to choose the form of surfaces a and b so that the measurements really indicate the frictional effect between liquid and liquid whatever the form of the surfaces of these elements may be, it is advisable that they terminate in a sharp point or line so that the frictional eflect of-those points which are immediately in contact with the moving liquid is reduced to a minimum. Obviously, the various toothed elements on cylinder '11 should project outwardly substantially to the same height and the same should be true for the toothe'delements formed inside of b. What I claim is 1.v In an apparatus of the class described, the combination of a pair of rotatable elements having surfaces out of contact with one another, each'of said elements having a plurality of protruding portions formed thereon adapted to take hold of a liquid in contact therewith, means for rotating one of said elements, and means for exerting a braking action on the other element.

2. An apparatus for measuring the internal friction of a liquid comprising a pair of rotatable elements mounted'out of contact with one another,-each of said elements being provided with a plurality of .ribs

tapering radially, said ribs being adapted to take hold of a. liquid in contact therewith, means for rotating one of said elements, and means for exerting a braking action on the other element.

In testimony whereof my hand. JEAN GEORGES DINTILHAC.

I have hereunto set 

